.270 vs .280

Which do you prefer?

  • Total voters
    436
270 140 gr. Accubond @ 3000 fps
500 yard velocity - 2155 fps
500 yard energy - 1443 ft-lbs
500 yard bullet drop from 100 yard zero - 44.5"
500 yard wind drift in 10 mph crosswind - 16.0"

280 140 gr. Accubond @ 3000 fps
500 yard velocity - 2135 fps
500 yard energy - 1420 ft-lbs
500 yard bullet drop from 100 yard zero - 44.8"
500 yard wind drift in 10 mph crosswind - 16.4"

No difference whatsoever
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Yeah the difference is so slight as to be none... but it proves what I was saying to senior that all things being equal the longer thinner bullet will out perform the shorter fatter one at long range...if the bullets are the same weight, design and start out at the same speed :roll: I know it is a very slight difference and I am nit picking..... I am just glad .280 Ackley didn't start in on me...he would have killed me in this debate :oops:
 
I'll email you the data in it's complete form Ignore the gun label - i forgot to change it from ruger 30-06, it's meaningless :)
 
Aww REDD your just lucky I had to slip off to that work thingy :roll:

I always agreed with your statement " but it proves what I was saying to senior that all things being equal the longer thinner bullet will out perform the shorter fatter one at long range...if the bullets are the same weight, design and start out at the same speed I know it is a very slight difference and I am nit picking..... "

I was just stateing that a 280 with slightly more case capacity, if loaded to same pressure should be 50fps faster, thus equal or miniscully better!

I also can't figure the arguement the 280 was light loaded for the jamomatic :?: when the same gun shoots the 270 :?: :roll:
 
I use JBM Ballistics software

http://www.eskimo.com/~jbm/ballistics/calculations.html


It's more fair to compare bullets of similar sectional density rather than bullet weight. Like a 140 gr. .277" bullet has a SD of .261, and a 140 gr. .284" bullet has a SD of .248, close, but not identical. Closer would be the 130 gr. 277 (.242) and the 140 gr. 7mm. Or a 140 gr. 277" and a 150 gr. 7mm (.266), or a 150 gr. .277" (.279), vs a 160 gr. 7mm (.283).

The slightly larger bore diameter of the 280 gives a larger push area on the expanding powder gases, and the 280, loaded to same pressures, will always shoot slightly faster than a 270 with the same bullet weight, usually by 50 fps. The usually higher BC of the higher S.D. 270 bullet will retain velocity a bit better, thus downrange, the initial velocity advantage the 280 held is gone. Does any of this make sense??
headscratch.gif


Who here wants me to shut up now?
banghead.gif


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tb
 
senior said:
I also can't figure the arguement the 280 was light loaded for the jamomatic :?: when the same gun shoots the 270 :?: :roll:
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Just because you don't understand somethign doens't make it untrue...

The original loadings of the .280 were 50 000 PSI. The .270 had a rating of 52 000 psi...

The .280 was introduced in the 740 rifles.
 
swait tunderin lardee byes I don't follow none of dis stuff. where's me rum????

Doug
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Don't bring remington ultra mags into this for heaven's sake doug, we'll never be finished.....
 
BIGREDD said:
Yeah or a .270 short mag.... I averaged 3160fps with 71.0 grains of Retumbo and the 140 accubond... only 14fps variance... and half minute groups at 200 yrds... I got over 3200 fps using IMR4831 and no pressure problems but the accuracy was not as good and the recoil was up there...the Retumbo is very user friendly :wink:
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The difference on the shoulder was very noticing. I shot it too.
Even in the 300 RUM, Retumbo (W 200 gr accubonds, Chilly's rifle) was more mild on the shoulder than the factory 180 gr Scorocco loads for the 300 RUM.

I got 3020 out of a 160 gr Partition and 3170 out of a 139 gr BT out of my 23 inch 7mm mag. Ho Hum, thats why its gonna become a 358 WSM in the new year. (it'll be like christmas all over again :lol: )
Ruger #1
 
BIGREDD said:
I nominate Redd as the official, CGN, "S/D & B/C" Guru
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I know your being "facetious" Super... I already have enough trouble keeping my "#### Disturber" title... :wink:
Are you agreeing with me on the 6.5/.260 :?:
Do you think that S/D and B/C are a good way to compare calibres/cartridges... I think that they are a better indicator of performance on game than just bullet weight and velocity :idea:
It was the mystery of why the 6.5 performed so well on Big Game that opened my eyes to Sectional-Density in the first place :? 8)
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Hey Redd..........To answer your question....I own a .264Mag and don't plan on ever selling or trading it :D


SC........................
 
Hey Redd.........Santa Chilly and not so small elf will be sure to deliver a crony under your tree :wink: The old one suffers from a RUM hangover and you O.D'd it on WSM pills :lol:

So very enlightening fella :shock: A guy can't help to learn a whole bunch of #### in these discussions :wink: Good work man! :D
 
Super admits:
Hey Redd..........To answer your question....I own a .264Mag and don't plan on ever selling or trading it
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I kinda figured you already knew what I was talking about Super :wink:
Chilly say:
A guy can't help to learn a whole bunch of #### in these discussions
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Yeah thats why I stick my neck out in the first place... to learn something... there are some hunters on this site that have so much practicle knowledge they could write a thesis on killing game ... It kills me when I read some of the "so-called outdoor writers" espousing their expertise...when I know a dozen guys on Gunnutz that have shot more game than the "expert" has ever seen :wink: :lol:

Todd knew it from the start:
It's more fair to compare bullets of similar sectional density rather than bullet weight. Like a 140 gr. .277" bullet has a SD of .261, and a 140 gr. .284" bullet has a SD of .248, close, but not identical. Closer would be the 130 gr. 277 (.242) and the 140 gr. 7mm. Or a 140 gr. 277" and a 150 gr. 7mm (.266), or a 150 gr. .277" (.279), vs a 160 gr. 7mm (.283).

The slightly larger bore diameter of the 280 gives a larger push area on the expanding powder gases, and the 280, loaded to same pressures, will always shoot slightly faster than a 270 with the same bullet weight, usually by 50 fps. The usually higher BC of the higher S.D. 270 bullet will retain velocity a bit better, thus downrange, the initial velocity advantage the 280 held is gone. Does any of this make sense??

Who here wants me to shut up now?
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Not me Todd... you must get frustrated when trying to explain this techinical stuff to some of us though... you definitely grasp the science of ballistics better than I... sometimes I get a Mental picture of you laughing maniacally and sending your army of twisted emoticons out to slay the mere mortals... 8) :lol: :lol: :lol: :wink:
 
BIGREDD said:
... It kills me when I read some of the "so-called outdoor writers" espousing their expertise...when I know a dozen guys on Gunnutz that have shot more game than the "expert" has ever seen :wink: :lol:
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Are you saying that you don't believe the words of great outdoor personalities such as O'Conner and
Carmichal , who traveled the whole world shooting different animals , and who made a living telling about it ?They probably hunted 9 months out of a year where-as we are lucky if we can hunt 3 months .
 
Keepa argues:
Are you saying that you don't believe the words of great outdoor personalities such as O'Conner and
Carmichal , who traveled the whole world shooting different animals , and who made a living telling about it ?They probably hunted 9 months out of a year where-as we are lucky if we can hunt 3 months
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I don't know about you but hunting and shooting is a full time endeavor for me Keepa... sorry about your luck :oops:
Please don't equate the Greats with the Wannabes... and don't presume to put words in my mouth :twisted: I am not talking about any of the great writers... there are not too many of them left. :(
We seem to have a plethora of writers nowadays who just regurgitate and plagarize and say nothing new or intelligent... just like many on this site... who only contribute insignificant and confrontational drivel... or post contradictory and quarrelsome twaddle in the misguided hope that it will mend their insignificant existence :| :lol: :arrow: :idea:
 
I agree with Redd you cant compair guys like O'Conner and Capstick to guys like shocky who run around hiring guides to find there animals then whine in there articles that the plane ride was ruff and long :lol: , A true writer respects all aspects of the hunt good and bad without holding any regrets in the end , everyone has ther good and bad experiences and there fair share of problems but no one wants to hear how buddy shot at 3 deer in a weekend and couldnt find them but his rifle nocks beercaps off a fencepost @ 100 yards :lol:
 
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